Research On Path Planning Method For Mobile Robot Under Dynamic Environment

Path planning technology is a key part of mobile robot navigation systems.The path planning of mobile robots under dynamic environment means that planning a collision-free path from the starting point to the target point in an unknown environment.The key issue is how to plan an optimal path that can avoid obstacles in real time.In order to solve this problem,this paper proposes to apply fireworks algorithm in path planning.A double-level algorithm combining the global path planning based on improved fireworks algorithm and the local collision avoidance based on rolling window is proposed for path search.The algorithm embodies certain advantages in both path optimization and real-time performance.The main research contents are as follows:1.The environment of the mobile robot's workspace needs to be modeled before the path search.First,the workspace space is converted into a two-dimensional plane.The grid method is used to identify the workspace,and then the processed environment information is mapped to the grid map.In addition,taking into account the safety of the path,the acquired obstacle information is expanded by half the maximum length and width of the robot in the grid diagram,so that the robot can move collision-free along the planned path without collision.2.This paper applies research on fireworks algorithm(FWA).First,the basic fireworks algorithm and enhanced fireworks algorithm(EFWA)are applied to the path planning,and then the "regression-punishment" strategy is adopted to solve the problem of the path entering the deadlock state.For the problem that the explosion radius of the enhanced fireworks algorithm does not use the local information of the search process,the dynamic search radius strategy of the core fireworks is used for improvement.Through the comparison of simulation experiments,we can see that the improved fireworks algorithm improves the path,and improves the convergence speed and stability.3.In order to meet the real-time requirements of the local path planning,the search time of the path needs to be shortened.The migration operation in the biogeography-based optimization(BBO)algorithm is applied to the fireworks algorithm to form the firework algorithm based on biogeography optimization.And the number of fireworks is set as a constant,then the Gaussian mutation operator is eliminated and the elite selection strategy is implemented.The comparison of BBO,FWA and BBO-FWA through simulation experiments shows that BBO-FWA has the shortest path planning time and it is suitable for local pathplanning that requires real-time performance.4.In order to solve the optimal path problem and real-time problem of path planning of mobile robot in dynamic environment,this paper adopts the double-layer path planning method.In order to select the algorithm that can plan the optimal path,the path fitness function composed of path length,security and smoothness is firstly proposed.Then the improved fireworks algorithm,MBOA and PSO are compared through simulation experiments.The experimental data shows that the path of improved fireworks algorithm is optimal,so improved fireworks algorithm is selected for the first-level offline global path planning.The second layer uses a local collision avoidance algorithm based on a rolling window,and proposes a corresponding collision prediction method and collision avoidance strategy based on the motion direction of the dynamic obstacle.For the case where the local path needs to be re-planned,a new local path is planned by BBO-FWA.Simulation experiments demonstrate the effectiveness of the double-level algorithm.